Iris C. D. Westendorp

Associations of C-Reactive Protein With Measures of Obesity, Insulin Resistance, and Subclinical Atherosclerosis in Healthy, Middle-Aged Women

Obesity, the insulin resistance syndrome, and atherosclerosis are closely linked and may all be determinants of an increased acute-phase response. In this study, we examined the relationship of C-reactive protein (CRP) with measures of obesity, variables of the insulin resistance syndrome, and intima-media thickness of the common carotid arteries in 186 healthy, middle-aged women selected from the general population. Associations were assessed by regression analysis. CRP was strongly associated with body mass index (BMI) and waist circumference. CRP was also associated with other variables of the insulin resistance syndrome, including blood pressure, insulin, high density lipoprotein cholesterol, triglycerides, apolipoprotein A1 (inversely), plasminogen activator inhibitor-1 antigen, and tissue-type plasminogen activator antigen. Associations between CRP and the variables of the insulin resistance syndrome disappeared after controlling for BMI but remained significant for plasminogen activator inhibitor-1 antigen only. The association of CRP with common carotid artery intima-media thickness was weak and limited to ever-smokers. BMI explained 29.7% of the variance of CRP, whereas common carotid artery intima-media thickness explained only 3.7%. The results of this population-based study indicate that adiposity is strongly associated with CRP in healthy, middle-aged women. In this population, BMI accounted for the relationship between CRP and other variables of the insulin resistance syndrome. Further studies should determine whether losing weight ameliorates the inflammatory state.

Increased plasma homocysteine after menopause

Besides genetic defects in the enzymes involved in homocysteine metabolism and nutritional deficiencies in vitamin cofactors, sex steroid hormones may modulate plasma homocysteine levels. The post-menopausal state has been found to be associated with higher plasma homocysteine levels, but data are inconsistent and studies published so far did not adjust for age, which is an important confounding factor in studying the effect of menopause. In the present study total plasma homocysteine levels were measured in a meticulously selected population in which the contrast in estrogen status between pre- and postmenopausal women of the same age was maximized. The study comprised 93 premenopausal and 93 postmenopausal women of similar age (range 43-55 years). Women were selected from respondents to a mailed questionnaire on menopause, which was sent to all women aged 40-60 years in the Dutch town of Zoetermeer (n = 12675). Postmenopausal women who were at least three years after menopause or whose menses had stopped naturally before age 48 were age-matched with premenopausal women with regular menses and without menopausal complaints. Plasma homocysteine levels in the fasting state were related to menopausal status; the age-adjusted geometric mean was 10.7 micromol/l in premenopausal and 11.5 micromol/l in postmenopausal women (difference of 7%, 95% confidence interval 0.3-14%, P = 0.04). Additional adjustment for plasma creatinine, body mass index, smoking habit (yes, no) and alcohol intake did not influence this difference. The results of this population-based study indicate that plasma homocysteine is affected by menopause.

Menopausal status and risk factors for cardiovascular disease.

Abstract Peters HW, Westendorp ICD, Hak AE, Grobbee DE, Stehouwer CDA, Hofman A, Witteman JCM (Erasmus University Medical School, Rotterdam; Utrecht University, Utrecht; Vrije Universiteit, Amsterdam, The Netherlands). Menopausal status and risk factors for cardiovascular disease. J Intern Med 1999; 246: 521–528.

Variables of the insulin resistance syndrome are associated with reduced arterial distensibility in healthy non-diabetic middle-aged women.

Aims/hypothesis. The insulin resistance syndrome is related to arterial stiffness in diabetic subjects. Whether the insulin resistance syndrome is also related to arterial stiffness in non-diabetic subjects is less clear. We studied the association between variables of the insulin resistance syndrome in relation to arterial distensibility in healthy middle-aged non-diabetic women. Methods. This study was done in 180 non-diabetic women, aged 43–55, selected from the general population. Arterial distensibility was assessed in the carotid artery. The associations were evaluated using linear regression analyses. Results. Strong associations were found between arterial distensibility and the variables of the insulin resistance syndrome: body mass index, waist-to-hip ratio, high-density-lipoprotein-cholesterol, triglycerides, glucose, insulin, apolipoprotein A1, plasminogen activator inhibitor-1-antigen and tissue-type plasminogen activator-antigen. After additional adjustment for mean arterial pressure, common carotid arterial distensibility remained associated with body mass index: β-coefficient (95 % confidence interval) per kg/m2: –0.24 (–0.42; –0.06); waist-to-hip ratio: –26.62 (–40.59; –12.65) per m/m; triglycerides: –1.42(–2.77; –0.08) per mmol/l; plasminogen activator inhibitor–1-antigen: –0.01 (–0.02; –0.00) per ng/ml and borderline significant associated with high-density-lipoprotein-cholesterol: 1.93 (–0.01; 3.87; p = 0.07) per mmol/l. Clustering of variables of the insulin resistance syndrome was strongly related to decreased arterial distensibility which remained after adjustment for mean arterial pressure. No association was found between arterial distensibility and variables that are not part of the insulin resistance syndrome: total cholesterol, LDL-cholesterol and apolipoprotein B. Conclusion/interpretation. The results of this study show that variables of the insulin resistance syndrome are associated with decreased arterial distensibility of the common carotid artery in healthy non-diabetic subjects. [Diabetologia (2000) 43: 665–672]

Hormone replacement therapy and intima-media thickness of the common carotid artery: the Rotterdam study.

BACKGROUND AND PURPOSE Observational data suggest that hormone replacement therapy (HRT) reduces morbidity and mortality from cardiovascular disease in healthy postmenopausal women. The mechanisms underlying this protection are not entirely clear but may include inhibition of the atherosclerotic process. METHODS We studied the association between ever use of HRT and intima-media thickness (IMT) of the common carotid artery in 1103 naturally menopausal women, aged 55 to 80 years, in the Rotterdam Study, a community-based cohort study in a suburban area of Rotterdam, Netherlands. Mean and maximum IMT of the common carotid artery were measured noninvasively with B-mode ultrasound. RESULTS Ever use of HRT for >/=1 year was associated with a decreased mean and maximum IMT compared with never users (mean IMT, 0.719 mm [SE 0.01] versus 0. 742 mm [SE 0.004], P=0.03; maximum IMT, 0.952 mm [SE 0.015] versus 0. 983 mm [SE 0.006], P=0.04), after adjustment for age, smoking, educational level, systolic blood pressure, and body mass index. No association was found for use <1 year (mean IMT, 0.739 mm [SE 0.013] versus 0.742 mm [SE 0.004], P=0.69; maximum IMT, 0.990 mm [SE 0.019] versus 0.983 mm [SE 0.006], P=0.75). Additional adjustment for diabetes, frequency of visits to healthcare facilities, or total and HDL cholesterol did not change these results. CONCLUSIONS The findings of this population-based study show that ever use of HRT is associated with a decreased IMT in the common carotid artery in elderly women.

Hormone replacement therapy in perimenopausal women and 2-year change of carotid intima-media thickness

OBJECTIVES To assess the 2-year effects of a combined regimen of oral 17beta-estradiol and desogestrel (17betaE-D) and a sequential combination of conjugated equine estrogens and norgestrel (CEE-N) on common carotid intima-media thickness and end-diastolic lumen diameter in comparison to placebo in perimenopausal women. METHODS The study was a single center, randomized, group-comparative, double-blind study with respect to the 17betaE-D and placebo groups and open with respect to CEE-N. After cycle 6, the blind was broken and the trial was continued as an open trial for another 18 months for the active study arms. The study included 121 perimenopausal women recruited from the general population. Common carotid intima-media thickness and end-diastolic lumen diameter were measured at baseline and cycle 24 with B-mode ultrasonography. RESULTS At cycle 24 small changes in intima-media thickness and lumen diameter were observed. Relative to placebo, changes in intima-media thickness were -0.009 mm [95% CI -0.045; 0.027] for 17betaE-D and -0.016 mm [95% CI -0.055; 0.024] for CEE-N. For end-diastolic lumen diameter the changes were -0.091 mm [95% CI -0.236; 0.055] and -0.125 mm [95% CI -0.820; 0.032] for 17betaE-D and CEE-N, respectively. CONCLUSIONS In this study among perimenopausal women a significant effect of 17betaE-D and CEE-N on common carotid intima-media thickness and lumen diameter could not be demonstrated. Although the sample size of the present trial is too limited to provide definite conclusions, the direction of the effect is in agreement with evidence from earlier studies on the effects of hormone replacement therapy in postmenopausal women.

Menopausal status and distensibility of the common carotid artery.

Although several studies have shown that exogenous estrogens have beneficial effects on arterial characteristics, the effect of endogenous estrogen on the vascular system is still unknown. In this study, distensibility, an indicator of arterial elasticity, of the common carotid artery was compared in pre- and postmenopausal women. The study comprised 93 premenopausal and 93 postmenopausal women of similar age (range, 43 to 55 years). Women were selected from respondents to a mailed questionnaire about the menopause, which was sent to all women aged 40 to 60 years in the Dutch town of Zoetermeer (n=12 675). Postmenopausal women who were at least 3 years past natural menopause or whose menses had stopped naturally before age 48, were age-matched with premenopausal women with regular menses and without menopausal complaints. The selection aimed at maximizing the contrast in estrogen status between pre- and postmenopausal women of the same age. Distensibility of the carotid artery was measured noninvasively with B-mode ultrasound and a vessel wall movement detector system. Arterial distensibility is expressed as the change in arterial diameter (distension, DeltaD) with the cardiac cycle, adjusted for lumen diameter, pulse pressure, and mean arterial blood pressure. Compared with premenopausal women, postmenopausal women had significantly lower arterial distension (DeltaD 370.5 microm [SE 9.5] versus 397.3 microm [SE 9.6]). These results suggest that the distensibility of the common carotid artery is negatively affected by natural menopause in presumed healthy women.

The effect of hormone replacement therapy on arterial distensibility and compliance in perimenopausal women: a 2-year randomised trial.

A single centre randomised placebo-controlled trial was performed to assess the 2-year effects of hormone replacement therapy compared to placebo on mechanical arterial properties in 99 perimenopausal women recruited from the general population. The trial was double-blind with respect to a sequential combined regimen of oral 17beta-oestradiol and desogestrel (17betaE(2)-D) and the placebo group and open with respect to combination of conjugated equine oestrogens and norgestrel (CEE-N). At baseline, distensibility and compliance of the common carotid artery were measured non-invasively with B-mode ultrasound and a vessel wall movement detector system, and the distensibility coefficient (DC) and compliance coefficient (CC) were calculated. Measurements were repeated after 6 and 24 months. Change in DC and CC in treatment groups was compared to placebo. After 24 months, changes for 17betaE(2)-D compared to placebo were -1.4x10(-3)/kPa (95% CI -4.4; 1.7, P=0.39) for DC and 0. 26 mm(2)/kPa (95% CI -0.01; 0.53, P=0.07) for CC. Changes for CEE-N compared to placebo were 0.4x10(-3)/kPa (95% CI -1.0; 1.9, P=0.79) and 0.11 mm(2)/kPa (95% CI -0.14; 0.37, P=0.40). For systolic blood pressure (SBP), diastolic blood pressure (DBP) and arterial lumen diameter no changes were found. In this study no significant differences in changes in distensibility and compliance were found between perimenopausal women using 17betaE(2)-D or CEE-N and women using placebo after 6 and 24 months.